It doesn't, but that isn't their point. They're simply pointing out that existing net neutrality laws in the US usually only apply to ISPs and telcos, not internet businesses.

Nobody is defending the practice, they're just differentiating it from what we've previously referred to as "net neutrality," which is 100% entirely about how ISPs process internet traffic, and not about the services being used within that traffic.

Unless I missed the memo, and "net neutrality" means something different now.

Where did I say it did? The fact that it's not a net neutrality issue doesn't mean it's not an issue. Net neutrality is just a specific thing that isn't this.